Some time ago I bougth an Isoma centering microscope with ans SK40 adaptor. However I have no SK40 machine at all. During the last days I have been turning a cylindric tail which let me to use the microscope in the lathe as well as in the milling machine.

The part was dimensioned from an original one. It is a M15x0.75 threaded end with two main features:

  1. A 16mm bushing guide that assures concentricity, and
  2. A mating ring that assures perpendicularity.

Both features must be perfectly aligned to the cylindrical tail to guarantee the best aligment between the microscope center and the tail.

Following you can see some pictures of the original part (the ISO cone was cut away), the microscope, and the new cylindric tail.